Coppen, Helen Elizabeth <br/><br/>
Aids to teaching and learning / 
Helen Coppen. 
 - Oxford, Ing. :  Pergamon,  1969. 
 - 230 p. :  il. 
 - The Commonwealth and International Library of Science Technology Enginering and Liberal Studies .
<br/><br/><label>Encabezamiento--Tema: </label><br/>ENSEÑANZA ---MATERIALES AUXILIARES